The present invention relates to a process for the preparation of ethyl 3-ethoxy4-ethoxycarbonyl-phenylacetate having formula 1. 
Ethyl 3-ethoxy-4-ethoxycarbonyl-phenylacetate (1) is an important key intermediate for the synthesis of repaglinide (2) an oral hypoglycemic agent. 
Repaglinide (+) 2 ethoxy-4[N-{1-(2-piperidinophenyl)3-methyll-butyl}aminocarbonyl methyl]benzoicacid having formula 2 is from a class of hypoglycemic agents for type II non insulin dependant diabetes mellitus.
Hitherto known process for the preparation of ethyl 3-ethoxy-4-ethoxycarbonyl-phenylacetate having formula 1 involves two methods as shown below
Route 1 (J. Med. Chem. 1998, 41, 5219)
1. Alkylation of 4-methylsalicylic acid with ethyl bromide at 150xc2x0 C. for 30 hrs in autoclave to give ethyl 2-ethoxy-4-methyl benzoate of formula 3. 
2. Bromination of ethyl 2-ethoxy-4-methyl benzoate of Formula 3 with N-bromo succinamide to give ethyl 4-bromomethyl-2-ethoxybenzoate of formula 4. 
3. Cyanation of compound of formula 4 with sodium cyanide to give ethyl-4-cyanomethyl-2-ethoxybenzoate of formula 5. 
4. Treatment of gaseous HCL with ethyl-4-cyanomethyl-2-ethoxybenzoate in ethyl alcohol to give ethyl 3-ethoxy-4-ethoxycarbonyl-phenylacetate of formula 1. 
Route 2 (PCT WO 01/3590, 2001)
1. Alkylation of 4-methylsalicylic acid with ethyl bromide in dimethyl sulfoxide to yield ethyl-2-ethoxy-4-methylbenzoate of formula 3. 
2. Carbonylation of ethyl-2-ethoxy-4-methylbenzoate with lithium diisopropyl amide and carbon dioxide at xe2x88x9280xc2x0 C. in presence of HMPA gave 3-ethoxy-4-ethoxycarbonyl-phenylacetic acid of formula 6. 
The prior art processes have following drawbacks.
a. The alkylation of 4-methylsalicylic acid involves the use of ethyl bromide which is low boiling reagent, inconvenient for industrial handling.
b. The alkylation of 4-methylsalicylic acid requires dimethylsulfoxide solvent which is not safe for industrial scale.
c. The alkylation reaction requires high pressure and long duration.
d. The use of with lithium diisopropylamide reaction is not easier to handle on industrial scale.
The main object of the present invention is to provide a new process for the preparation of ethyl 3-ethoxy-4-ethoxycarbonyl-phenylacetate of formula 1 which obviates the drawbacks of the prior art processes and use cheaper and easily available chemicals.
Accordingly the present invention provide a new process for the preparation of ethyl 3-ethoxy-4-ethoxycarbonyl-phenylacetate of formula 1 which comprises
a. reacting 4-methylsalicylic acid with diethyl sulfate in presence of potassium carbonate in polar organic solvent at a temperature in the range of 50-80xc2x0 C. for a time period in the range of 6-12 hrs, filtering the product obtained, removing the organic solvent by evaporation and distilling the residue to obtain ethyl-2-ethoxy-4-methylbenzoate of formula 3. 
b. brominating ethyl-2-ethoxy-4-methylbenzoate of formula 3 with a brominating agent in organic solvent at temperature in the range of 40-60xc2x0 C. to obtain ethyl-4-bromomethyl-2-ethoxy benzoate of formula 4. 
c. Reacting ethyl-4-bromomethyl-2-ethoxy benzoate with CO in ethyl alcohol at a temperature in the range of 30-50xc2x0 C. for the period in the range of 14-24 hrs, in the presence of a palladium catalyst, removing the solvent by evaporation to obtain ethyl 3-ethoxy-4-ethoxycarbonyl-phenylacetate of formula 1 
In one embodiment of the invention the organic solvent used in step (a) for the reaction is selected from the group consisting of acetonitrile, acetone and dioxane.
In another embodiment of the invention the brominating agent used in step (b) is selected from 1,3-dibromo-5,4-dimethylhydantoin and N-bromosuccinamide.
In another embodiment of the invention the palladium catalyst used is selected from dichlorobis(1,2,5-triphenylphosphole)palladium and dichlorobis-(tripbenylphosphine)palladium.